Use of holograms in lighting applications is known in the art. For instance, U.S. Pat. No. 5,497,251 discloses a hologram structure for use in a holographic center high-mounted stoplight system for a vehicle. The hologram structure includes an illumination source for providing a reconstruction beam, a first array of non-overlapping hologram cells and non-hologram cells, and a second array of non-overlapping hologram cells and non-hologram cells. Each hologram cell of the first array produces a specular image that is viewable in a first predetermined angular field pursuant to diffraction of a portion of the reconstruction beam, and each hologram cell of the second array produces a diffuse image that is viewable in a second predetermined angular field pursuant to diffraction of a portion of the reconstruction beam. The specular images and diffuse images produced by the first and second holograms form stoplight illumination. In this way, a stoplight should be provided that has an output with an appearance that is similar to the lenticulated output of a conventional headlight.
U.S. Pat. No. 4,722,037 discloses an optical assembly for providing illumination comprising (a) a first artificial light source providing light at a first wavelength, (b) a second artificial light source providing light at a second wavelength different from said first wavelength, and (c) a holographic optical element adapted to diffract light of said first and second wavelengths in different beam patterns, and positioned in such a way that light from said first and second light sources is diffracted in said different beam patterns to provide illumination of two different regions in space. The optical assemblies according to U.S. Pat. No. 4,722,037 should provide an improved efficiency and reduced glare by producing multiple beam patterns, using a plurality of light sources of different spectral characteristics, and a holographic optical element adapted to diffract light from the two light sources into different beam patterns. The optical assemblies according to U.S. Pat. No. 4,722,037 should be useful as automobile headlights to produce high or low-beam illumination of the roadway, depending on which light source is turned on.
U.S. Pat. No. 5,571,277 discloses an automotive signal lamp comprising a first light providing a source of illumination, a tinted lens receiving the illumination by the first light source on a first side of the lens, the lens tinting the illumination given by the first light source to a first desired frequency, a transmissive hologram adjacent the lens for providing a first image only when the first light source is actuated, the transmissive hologram being activated by light at the first desired frequency, and a reflective hologram adjacent the transmissive hologram for providing an image differing from the first image, the second image being visible only when the first light source is not actuated and when the lens is illuminated by a second light source on a side of the lens generally opposite the first light source.